This now abandoned restaurant provides some of the most amazing views of Lisboa.

This tile-work piece featuring a chicken riding in carriage is both a remarkable artistic creation and a social commentary of politics and culture in 17th-century Portugal.

The tunnel's elegant proportions keep you snug with no claustrophobia freak-out.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

The best preserved Paleochristian basilica in Rome hides a number of oddities and secrets.

A huge enchanting public park just outside the ancient walls of Rome.

Macabre museum devoted to historical Viennese murders.

Fascinating exhibits of prehistoric and ancient artifacts displayed with a uniquely modern touch.

A slice of central Asia in the middle of Berlin.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

This tribute to the 16th-century composer is now an unusual shrine to Michael Jackson.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

Some people believe that this makeshift space monitoring station received transmissions from clandestine cosmonauts.

A Turkish ghost town abandoned in a population exchange with Greece.

This charming fountain honors Felix Salten, the creator of the iconic storybook deer.

The Swiss artist's bulbous and overgrown shape-shifting sculpture controversially graces the center of Bern.

Extensive private collection of authentic Medieval devices used for human torture and execution.

This colorful but controversial ceiling has been likened to a 21st-century Sistine Chapel.

See the rare bloom of the "Queen of the Night" cactus at one of the world's largest succulent collections.

Walk through a restaurant's refrigerator door to reach this hidden bar.

For centuries no one knew there were hundreds of bones and precious artwork hidden beneath this Swiss church.

This amazing pedestrian suspension bridge in the Swiss Alps would give Indiana Jones nightmares.

The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

The largest Neolithic ruins in the world hide a notably clean prehistoric metropolis.